Pressure resisting heating vessel



Nov. 20, 1951 K. K. K. KRZYER PRESSURE RESISTING HEATING VESSEL .2 SHEETSSHEET l Filed Nov. 1, 1946 fTruK EYS 2 1951 K. K. K. KRQYER 2,575,567

PRESSURE RESISTING HEATING VESSEL Filed NOV. 1, 1946 2 SHEETSSHEET 2 QTTORAIEYS Patented Nov. 20, 1951 PRESSURE RE SISTING HEATING VESSEL Karl Kristian Kobs KrcyenAarhus, Denmark Application November 1, 1946, Serial No. 707,083 In Denmark January 29, 1946 1 Claim.

The present invention relates to a pressure resisting heating vessel adapted to be employed in all dimensions and for all purposes, such as for pressure cookers for domestic and restaurant purposes and for autoclaves.

It is known to construct vessels of the kind in question in such a manner that the pressure in the interior of the vessel contributes to increasing the tightening between vessel and cover instead of counteracting same, as the case when the tightening eifect is efiected by means of a packing or washer clamped between the vessel and the cover. Such an increase of the tightening effect under the influence of the pressure is obtained by means of packing or tightening members which under the influence of the pressure in the interior of the vessel are pressed against tightening surfaces of the vessel and the cover. Hence, when applying the cover to the vessel no tightening of nuts or the like has to be effected in order to clamp a packing or washer, but it will suflice to provide stop means preventing the cover from rising from the vessel. The well known advantages of such constructions are simplicity in design and automatic tightening irrespective of the greater or smaller care with which the device is handled.

The present invention has for its purpose to construct a vessel of the above mentioned general class, and which is simple in design; cheap to manufacture; absolutely safe and reliable in operation; and extremely easy to handle, and with these and other purposes in view a vessel of the kind in question, according to one feature of the invention, comprises a vessel body, a cover,

Fig. 5 a modified construction of a pressure cooker with its cover applied, in top view, and

; embodiment.

means for tightening the joint between the vessel body and the cover under the influence of the inside pressure, gripping means associated with said vessel body and said cover, and a looking ring of variable diameter adapted in one diameter position to engage behind the gripping means of the vessel body and the cover and in another diameter position to pass free of the gripping means of one of the said members.

Further details and characteristics of the invention will appear from the following specification with reference to the accompanying drawing in which Fig. 1 shows a pressure cooker with its cover applied, in top view,

Fig. 2 on a larger scale a fracture of same with the parts in one position,

Fig. 3 the same as Fig. 2 with the parts in another position,

Fig. 4 a vertical section through the joint between the vessel and the cover,

In the drawings, l is the vessel body and 2 the cover. As appears from Fig. 4, the vessel body and the cover are provided at their'edges with bent portions 3 and 4 respectively, which com-- bine to form a groove 5 for receiving a tightening ring 6, e. g.consisting of India rubber. The dimensions and the shape of the bent portions 3 and 4 are selected in such a manner that when the cover is applied to the vessel the tightening ring 6 will be clamped in the groove 5 before or when the free edges 1 and 8 of the vessel and the cover respectively contact with each other, so that the tightening ring 6 is thereby caused to close the bottom of the groove 5. This construction of the tightening means is particularly advantageous and operates in the following man ner: When the cover is applied to the vessel and is subsequently prevented from rising from the latter in a manner to be described in the following, the tightening ring 6 is pressed lightly against the walls of the groove between the ves sel and the cover, so as to cause a provisional tightening effect, when a pressure above that of the atmosphere begins to come up in the vessel. This provisional tightening effect is at any rate suflicient for the pressure to develop in the interior of the vessel, and when this takes place the tightening ring 1, under the influence of the pressure, will be pressed towards the bottom of the groove 5 so as to tighten the gap 9 between the vessel and the cover.

The tightening ring 6 need not necessarily consist of India rubber, but may, according to circumstances such as the size of the vessel, the pressure at which the vessel operates etc. consist of any suitable material, and it may also be composed of a plurality of different parts such as a metal portion expanding under theinfluence of heat and thereby contributing to the tightening'efiect, the said metal portion being coated with a suitable tightening material, or alternatively a ground-in tightening portion oi harder material may be used.

To the edge of the vessel a re-inforcement ring I0 is attached which carries a number of teeth H, and similarly the cover is provided with a re-inforcement ring l2 carrying a number of teeth l3. The re-inforcement ring and the teeth may, if desired, be integral with the vessel and the cover. The teeth II and I3 are disposed in from the. vessel .mayslide radia-Hyinwards and outwards on the "teeth l3, when its diameter is varied in a manner to be described in the following. In the outermost or expanded position of the ring [4 shown in Fig. 4, the ring will not prevent the cover from being lifted from the vessel, but if the ring is displaced inwardlyon the teeth l3 so as to engage below'the teeth ll,

it will effectively prevent thei cover if'romrisingrelatively to the vessel.

For causing the said movements of the ring 14,

a well known rotatable tightening lever IS with an operating handle, but it is to be understood that any, other means may be used forthe' purpose. In Fig. 2 the tightening lever is shown in theposition correspondingto the expanded position of the ring, while in Fig. 3 the tightening lever is shown in the position corresponding to the contracted position of the ring, to wit the position'in which the ring prevents the cover from rising from the vessel. The cover is shown provided with a screw plug I! screwed into a hole in the lock and situated in such a position as to prevent a turning of the handle l6 of the tightening lever. Thus, when the cover is locked relatively to the vessel it is not possible to release such locking until the plug l1 has been unscrewed and thereby has permitted apressure equalisationto take place between the interior of the vessel and the surrounding atmosphere. The plug I! may advantageously contain a safety valve.

' In order that the co-operation between the plug [1 and the handle '16 should take place in the desired manner it is necessary that the handle it is always situated at a pretermined circumferential position'relatively to the cover, and also in'o'ther respects it is desirable that the ring as awhole should always assume a predetermined position relatively to the cover. In the embodiment shown this is obtained by providing the ring, at a suitable place of its circumference, preferably diametrically opposite to the tightening lever. with a bent-out portion 35 forming a {tongue'guided in a hole in one of the teeth of the cover. This 'hole accordingly forms a guide for the ring a ainst-displacement in the circumferential direction, and at the same time it forms a guide against displacement in an axial direction. Preferably a pin I8 is screwed into one of the teeth of the cover atanother circumferential position, which pin 18 forms another guide against-displacement in an axial direction. Thus, the ring as a whole is always held in a definite position relatively to the cover, but is nevertheless capable of performing the prescribed expanding and contracting movements.

- In Figs. '5 and 6, 2| is thevessel; and 22 the cover. A'tits edge the vessellhas an enlarged portion or re-infor'cement ring 23 adapted to be received in a bead-like collar or're-inforcement ring 24 on the cover 22. At "the top of the eniar'ged portion there is provided an exterior cylindrical surface 25, which-with a suitable play-forms a guide for a-corresponding interior cylindrical surface 25 olfv the cover. Moreover,

crating with a corresponding surface 28 of the cover. Immediately inside the surfaces 21 and 28 the enlarged portion 23 of the vessel as well as the cover 22 are constructed with a rounded crosssectional shape so that they combine to form a semi-circular groove for receiving a tightening ring 29 in similar manner. asinFigs. 1-4.

In the bead-.likecollar 24 of the cover 22 there is provided an annular groove 30 in which a flat locking ring 3! of variable diameter is mounted. At the bottom end of the cylindrical surface 25 and immediately above the position occupied by v the top wall of the groove 30 when the surfaces Y follows a cylindrical surface 33 of smaller dithe shown embodiment of-the invention comprises ameter than the cylindrical surface 25.

The diameter of the" ring 3! can be varied or, in other words, the ring can be expanded and contracted in any suitable manner, e. g. by means of a tightening lever with a handle 34 in an exactly similar-manner as in Figs. 1-4. Also the handle 34 may be arranged, in conformity with Figs. 1-4, to. co-operate with a plug 35-which may contain a'safety valve-in such a manner that the handle 34 cannot be turned until the plug 35 has been unscrewed. I

The operation is as follows: When the ring 3! is in its expanded position it is fully or all but fully plunged into the groove 39, and with the ring in this position thecover can be pushed on to the vessel until the surfaces 21 and 28 strike one another. Thereby the tightening ring 29 is subjected to a light pressure against the wall of the semi-circular groove formed by the rounded portions of the enlargement 23 and the cover 22. Now, the ring 3! is contracted by turning the handle 34. Thereby the ring 3| is moved partly out of the groove 33 and contacts with the cylindrical surface 33 of the enlarged portion 33, thus engaging below the shoulder surface 32. In this contracted'position of the .ring 3! it is centered tion 23, an annular shoulder surface 21 co-opby the cylindrical surface 33, while up to now it has been centered by the bottom of the groove 30 in its expanded position. Now, the plug 35 is screwed into its hole in the cover, and heat is applied to the vessel. vAs soon as a pressure above that of the atmosphere begins to come up in the interior of the vessel, this pressure will press the tightening ring 29 against the wall of the semicircular groove in which the tightening ring is accommodated.

As to the locking ring, all it has to do is to prevent the cover 22 from rising relatively to the vessel. This is effected by the locking ring being clamped between the shoulder surface 32 of the enlarged portion of the vessel 2| on one hand and the bottom wall of the groove 39 in the collar of the cover on the other hand. Of course there must be so much play that before such clamping takes place a small lifting movement of the cover occurs, so that the surfaces 21 and 28 are removed from contact with each other, but this .is .of no consequence since the gap between these surfaces is effectively tightened by the tightening ring 28.

The arrangement might of course as well be opposite to that shown, so that the groove in which the locking ring received is provided in the vessel proper, while the shoulder surface is provided on the cover. Further, the cover might engage with the vessel on its inside instead of its outside, and many other modificasaid cover body having edge portions forming complementary portions of a groove of substanl0 tially semi-circular cross section and having the joint between vessel and cover situated about mid-way of its height so as to subdivide the wall thereof into upper and lower wall portions each having a cross sectional shape substantially 15 forming a quarter of a circle, a removable sealing ring in said groove, said sealing ring having sufflcient height to be compressed between upper and lower wall portions of said groove to thereby provide provisional sealing when said cover body rests freely on said vessel body and there is no pressure in the vessel, said groove also having outer wall portions againstwhich said sealing ring may be pressed under the influence of a pressure in the vessel, an annular groove in one of said bodies, a locking ring of variable diameter accommodated in said groove and adapted at one diameter to be entirely in said groove and at another diameter to extend partly therefrom,

6 means for varying the diameter of said locking ring, and a shoulder surface on the other of said bodies engageable by said locking ring when in said other diameter position and having a free space behind it to allow for axial play of said locking ring behind said shoulder surface.

KARL KRISTIAN KOBS KRQYER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,137,085 Riddle Apr. 27, 1915 1,871,834 Astrom Aug. 16, 1932 2,086,044 Nelson July 6, 1937 2,133,060 Stephens Oct. 11, 1938 2,347,844 Sandberg May 2, 1944 20 2,414,529 Ives Jan. 21, 1947 2,441,131 Blackman et a1 May 11, 1948 2,463,516 Barkhardt Mar. 8, 1949 FOREIGN PATENTS 25 Number Country Date 420,113 Great Britain Nov. 26, 1934 437,138 Germany Nov. 15, 1926 490,788 Germany Feb. 10, 1930 

